Fix: thread-safe middleware singleton and re-enable repo stats schedule

Author: dsarno

.github/workflows/github-repo-stats.yml

@@ -1,10 +1,10 @@
 name: github-repo-stats
 
 on:
-  # schedule:
+  schedule:
     # Run this once per day, towards the end of the day for keeping the most
     # recent data point most meaningful (hours are interpreted in UTC).
-    #- cron: "0 23 * * *"
+    - cron: "0 23 * * *"
   workflow_dispatch: # Allow for running this manually.
 
 jobs:

Server/src/transport/unity_instance_middleware.py

@@ -16,14 +16,17 @@
 # Store a global reference to the middleware instance so tools can interact
 # with it to set or clear the active unity instance.
 _unity_instance_middleware = None
+_middleware_lock = RLock()
 
 
 def get_unity_instance_middleware() -> 'UnityInstanceMiddleware':
     """Get the global Unity instance middleware."""
     global _unity_instance_middleware
     if _unity_instance_middleware is None:
-        # Auto-initialize if not set (lazy singleton) to handle import order or test cases
-        _unity_instance_middleware = UnityInstanceMiddleware()
+        with _middleware_lock:
+            if _unity_instance_middleware is None:
+                # Auto-initialize if not set (lazy singleton) to handle import order or test cases
+                _unity_instance_middleware = UnityInstanceMiddleware()
 
     return _unity_instance_middleware